Background. An increasing number of studies are investigating traditional retreats. Very little, however, is known about their effectiveness.

Objective. To evaluate the effectiveness of meditation retreats on improving in general population. A total of 20 papers (N = 2912) were included.

Results suggested large effects on measures of anxiety, depression, stress, and moderate effects on measures of emotional regulation and quality of life. As to potential mechanisms of actions, results showed large effects on measures of mindfulness and compassion, and moderate effects on measures of acceptance.